Animal cage insert and convertible animal cage

ABSTRACT

A convertible animal cage particularly suited for use in laboratories utilizing more than one kind of small rodent to minimize storage area and cage inventories. In one embodiment, a standard hanging cage with a relatively large grid bottom and front is converted into a cage for smaller animals by the insertion of an L-shaped piece consisting of a smaller grid. In another embodiment, the front and bottom panels of an otherwise solid cage are replaced with panels of a different size grid.

This is a division of application Ser. No. 586,273, filed Mar. 5, 1984,now U.S. Pat. No. 4,524,721.

BACKGROUND OF THE INVENTION

The confinement of animals by various means extends back to prehistorictimes. As man has developed more specialized needs and varieties ofanimals, the means for their care has also evolved.

The maintenance of domestic animals in racks of cages is of relativelyrecent origin. Techniques and apparatus have been primarily aimed at theneeds of poultry, particularly chickens. For example, U.S. Pat Nos.3,726,255 to Marr and 4,046,107 to Kuster disclose cages designed toprevent such problems as breast blisters, swollen hocks, and snaggedtoes and feet in caged poultry. The U.S. Pat. No. 3,726,255 teaches amethod for preventing the breast and hock abrasions of chickens by theuse of a resilient mat placed over the standard cage floor. The U.S.Pat. No. 4,046,107 teaches the use of a movable panel of small grid sizeplaced over the regular floor of the cage to prevent the chickens feetfrom slipping through the cage.

A problem with both inserts is that the waste material no longer freelyfalls through the cage floor. In the case of the mat, resilient motionhelps the material pass through the openings. In the design using a hardinsert, the floor is bracketed so that the movement of the chickenpushes the two pieces together to help force the waste material throughthe smaller grid.

Developments over the last twenty to thirty years in science andindustry has promoted the keeping of animals other than poultry in racksof cages. These animals are primarily small mammals such as rabbits,rats, hamsters, guinea pigs, and mice.

The majority of cages for these animals are of standard construction,with four sides, one of which is a door, a top, and a bottom whichallows the waste material to pass through onto a collection pan. Anexample of such a cage where the panels disassemble for storage is U.S.Pat. No. 3,721,213 to Bruggeman.

Due to the distinctive demands of laboratory work, cages have beenfurther specialized so that they provide for the animal's comfort, areeasily cleaned and sterilized, and can be uniformly positioned onstorage racks to provide the maximum number of cages in the availablespace while maintaining adequate ventilation and spacing necessary toprevent the spread of disease.

The most common way to prevent the spread of disease through contact ofthe animals while insuring adequate ventilation is to design the cagewith an open or a solid top, three solid side walls, and an open gridedfront wall. The bottom must necessarily be an open grid to allow thewaste material to pass onto the collection tray below. Open toppedhanging cages that slide into brackets mounted on the underside ofshelves on the racks have the advantage that they do not require doorssince the underside of the shelf serves as a solid barrier (or top) forthe animal cage and access to the cage is easily provided by sliding thecage out from the rack to expose the open top. This allows the food andwater containers to be directly mounted on the front, open grided panelfor maximum utilization of area at a minimum cost.

A drawback to these cages is that, due to economic considerations, theyare constructed out of a single sheet of metal to which a grid isattached at the front and on the bottom. Not only do the cages not comeapart for storage, but they can only be used for one variety of animal,for example a rat, and not another animal of a different size, forexample a mouse. The mouse could escape through or be injured by thelarger grid used for containing a rat, and the waste material of thelarger animal, the rat, would not go through the smaller grid used for amouse.

As a consequence, cages of each grid size must be inventoried so thatthe required cage size is available when needed. This is expensivebecause extra cages must be purchased and because the extra cages mustbe stored when not in use.

It is therefore a principal object of the present invention to provide acage which is convertible for use with more than one variety or size ofanimal.

Another object of the invention is that the means of conversion notalter the size or ability of the cage to be cleaned and sterilized.

Yet another object of the present invention is that the means ofconversion is simple, inexpensive, reliable and can be stored in arelatively small area.

A still further objective of the present invention is that it not bedetrimental to the health and welfare of the caged animal.

SUMMARY OF THE INVENTION

The present invention is a convertible animal cage wherein the grid sizeof the front and bottom panels is changed to accommodate different sizeanimals. The remainder of the cage is utilized without alteration.

In one embodiment, a cage with a relatively large grid bottom and frontis converted into a cage for a smaller animal by the insertion of anL-shaped piece consisting of a smaller grid. In another embodiment, thefront and bottom panels are removed and panels of a different grid sizeinserted.

These and other features and objects of the invention will becomeapparent to those skilled in the art from the following detaileddescription which should be read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of a standard hanging rat cage with a solidback and sides, a large grid front and bottom, and an open top;

FIG. 2 is a perspective of an L-shaped insert of a smaller grid size forplacement inside the cage shown in FIG. 1;

FIG. 3 is a sectional view of the cage of FIG. 1 with the insert of FIG.2 in place;

FIG. 4 is a cross-sectional view of the insert and cage shown in FIG. 3taken along line 4--4 of FIG. 3;

FIG. 5 is a plain front view of the cage shown in FIG. 1 with bracketsfor the food and water containers;

FIG. 5A is a plain front view of a feed container-water bottle bracketcombination which attaches to the front of the cage as shown in FIG. 5;

FIG. 6 is a plain view of a hanging rat cage with front and bottompanels removed;

FIG. 6A is a composite view of the bottom panel, with two different gridsizes, for the cage shown in FIG. 6;

FIG. 6B is a composite view of the front panel, with two different gridsizes, for the cage shown in FIG. 6;

FIG. 7 is a perspective view of the cage shown in FIG. 6 with the bottomand front panels in place;

FIG. 8 is a detailed cross-sectional side view of the interface of thefront and bottom panels taken along line 8--8 of FIG. 7;

FIG. 8A is a detailed cross-sectional top view of the front panel, inplace in the cage, taken along line 8A--8A of FIG. 7;

FIG. 8B is a detailed cross-sectional side view of the bottom panel, inplace in the cage, taken along line 8B--8B of FIG. 7; and

FIG. 9 is a plain view of the bottom panel from the rear of the cagewith a portion broken away to show the bottom panel grid.

DETAILED DESCRIPTION OF THE INVENTION

One embodiment of the present invention is shown in FIGS. 1-5. In thisembodiment, an animal cage 10 consists of two solid sides 12 and 12', asolid back 14, and an open grid front 16 and bottom 18. The sides 12 and12' and back 14 are constructed from a single sheet of metal, such asstainless steel, which is bent at each corner 20 to form the three solidsides, 12 and 12' and 14. Slits are made at the corners 20, then theupper 22 and lower edges 24 are bent out and folded over, to form edgesat right angles to the back and sides. The upper edges 22 along thesides 12 and 12' slide into brackets on the bottom of shelves which arelayered to form multi-shelf racks. Multiple cages 10 can be hung alongthe length of the shelves. The front edges 26 of the metal sides arealso bent out and folded over. The front edge 26 and bottom edges 24form clamps to hold a piece of open grid in place on the front 16 and onthe bottom 18.

An L-shaped insert 30, shown in FIG. 2, is placed inside the cage 10 ofa larger animal, such as a rat, to convert the cage 10 into a cage for asmaller animal, such as a mouse. The cage 10 with the insert 30 is shownin FIG. 3. A sectional view of the insert within the cage is shown inFIG. 4. The grid size of the insert 30, is smaller than the grid size ofthe bottom 18 and front 16 of the cage 10. For example, a grid openingof 121 m² in area, plus or minus 10%, is used for a rat and a gridopening of 49 m² in area, plus or minus 10%, is used for a mouse. Thereis an opening 32 in the grid for access to the food and an opening 34for the water bottle.

FIG. 5 shows the front of the cage 10 with the water bottle opening 36and bracket 38 for holding the food container-water bottle bracket 40shown in FIG. 5A. The lower piece 42 on the food container 40 slips intothe bracket 40 on the cage 10, securing the container 40 next to thecage. A bracket 44 projects perpendicularly outward from the foodcontainer box 46 to hold a water bottle. The water bottle outlet entersthe cage 10 through the opening 36.

A second embodiment of the invention is shown in FIGS. 6-9. In thisembodiment the front and bottom gridded panels of the cage are replacedwith the appropriate grid size for the animal being confined in thecage. A solid bottom panel may be used with a front gridded panel if theanimal to be contained, such as a hamster, prefers nesting material toan open floor.

The basic cage 50 is shown in FIG. 6. The cage 50 consists of two solidsides 52 and 52' and a solid back 54. As with the first embodiment, asolid sheet of metal is bent at the corners 56 to form the sides 52 and52' and back 54. The metal is split at the top and bottom of the corners56, and the top of the sides 52 and 52' and back 54 bent out and backover to form edges 58 and 60 perpendicular to the sides 52 and 52' andback 54. The upper edges 58 slide into brackets on the bottom of theshelves in multiple shelf racks to hold the cages up against theundersides of the shelves. The lower edges 62 and 64 of the sides 52 and52' and back 54 are also bent out, down, and under to form a means forholding the bottom panel 66 shown in FIG. 6A. Pieces of metal 68, bentto form right angles, are affixed to the inside of the sides 52 to holdthe front panel 70. The panel 70 slides between these pieces 68 and thefront edges 72. The panel 70 is prevented from falling out of the cage50 by means of a flat piece 74 of metal welded to the top of the frontpanel 70. The front panel 70 protrudes in front of the bottom panel 66so that the bottom panel 66 is locked inside of the cage 50. Two panelgrid sizes 67 and 69, one for use with rats and having an opening ofapproximately 121 m² in area, and one for use with mice and having anopening of approximately 49 m² in area, are shown in FIGS. 6A and 6B. Asshown in the figures, the panels 66 and 70 consist of either open grid67 or 69 on a round metal frame 71.

The completely assembled cage 50 is shown in FIG. 7. The bottom panel 66slides into the bracket formed by the lower edges 62 and 64 and is thenheld in place by the panel 66 which is slid in between the pieces 68 andthe edges 72 at a right angle to the bottom panel 66.

A strip 76 of metal is welded across the front of the cage 50 to hold abracket 78 to secure the food container 40 by means of the piece 42 atthe bottom of the box 46. No openings in the front panel are necessarysince there is only one layer of wire, unlike the first embodiment inwhich an insert 30 is placed inside the cage 10. A second metal strip 80secures the top front portion of the cage.

FIGS. 8, 8A, 8B, and 9 show the actual construction of the panels 66 and70 and the way they are positioned within the cage 50. The extension ofthe front panel 70 in front of the bottom panel 66 is best shown in FIG.8. FIG. 8A shows how the front panel 70 is positioned between the frontedge 72 and the right angle piece 68. FIG. 8B shows how the bottom panel66 fits into the lower side edges 62. FIG. 9 is a view of the bottomrear portion of the cage 50. The bottom panel 66 is held by the sidebrackets 62 and rear bracket 64. A piece 81 of metal, cut to form aright angle, secures the corners 56.

These and other modifications of the invention will occur to thoseskilled in the art in the foregoing detailed description and theaccompanying drawings. Such modifications are intended to fall withinthe scope of the appended claims.

What is claimed is:
 1. A process for converting a hanging animal cagefrom being appropriate for one size animal species to a cage suitablefor use with a different size animal species, said processcomprising:(a) providing a cage having two solid sides, a solid back,and means for holding front and bottom grid panels; (b) providing aplurality of insertable front and bottom panels of different grid sizes,said grid size determined to be the appropriate grid to safely andhygienically cage a particular size animal species; (c) determiningwhich animal species is to be caged in a particular cage; and (d)inserting panels of appropriate grid size for the particular animalspecies to be caged into said means for holding the front and bottompanels of said cage.